Version:           unknown (using KDE 3.2.0, compiled sources)
Compiler:          gcc version 3.2.3
OS:          Linux (i686) release 2.4.22

The Treeview in Sidebar follows folder navigation in "View window" (that is "Treeview gets expanded by clicking on a folder in View window, not in tree" for all non Hidden folders. But It (tree-view-follow-folders) doesn't follow HIDDEN folders. 
 
How to Reproduce: 
 
1. Open $HOME folder 
2. Enable "Show Hidden Files" in Konqueror by clicking View->Show Hidden Files 
3. Click on HOME in Sidebar button 
4. Click and enter "Desktop" Folder 
5. You can see that side-tree gets expanded showing (getting selected) Desktop folder. 
 
6. Now Click BACK button to goto HOME and side-tree selection will move to HOME 
7. Now click and enter ".kde" folder or any folder with a "." as prefix (hidden) 
8. Now you can see that The tree doesn't show the .kde in the tree and won't work as expected. 
 
Expectation: 
 
1. Please add option to "Show Hidden folders in Side-tree" in View Menu (and) 
2. When clicked on a Hidden folder it should be shown (automatically)in the tree